This invention relates to an apparatus for purifying air flowing through a heating, air conditioning or other ventilation system, and more particularly to an apparatus which uses high energy microwave and ultraviolet radiation, along with an antimicrobial fluid to kill contaminants such as bacteria and viruses dispersed in the air flowing through the ventilation system. The invention further relates to a self-contained air purification module.
Various methods of removing bacteria viruses and other contaminants exist for use as stand alone system or as a module installed in a new or existing ventilation system. Various types of filters remove contaminants above certain size by physically separating particles over a certain size, which may include dust particles, bacteria and viruses. Other systems use energy in the form of light or radiation to kill undesirable bacterial and viral micro-organisms. Still other filtration systems use activated charcoal or a similar material to adsorb unwanted odors, airborne particles, cigarette smoke, and pollutants from the air in an enclosed space.
Many persons have attempted to improve air cleaners for ventilation systems. For example, U.S. Pat. No. 6,203,600 (Loreth) discusses a device for air cleaning. The device includes a precipitator for use in an air purification device, especially one removing electrically charged particles. U.S. Pat. No. 6,296,692 (Gutmann) discusses free standing air purifier enclosed in a housing, for use in cleaning the air in a room. The device uses an electrostatic air cleaning unit, operating at lower voltages, which ionizes debris contained in the air while eliminating ozone formation.
U.S. Pat. No. 5,779,769 (Jiang) illustrates a lamp including an indoor air purifier. The lamp draws air into its interior, through a purification system including activated charcoal and an electrostatic air cleaner, and expels it back into the room.
In U.S. Pat. No. 6,056,808 (Krause), an apparatus ionizes air to remove particulate matter. According to the patentee, high voltage electrodes ionize airborne particulates, and an ionic wind is created between the electrode and the duct. The use of high horsepower blowers enables use of the device in office buildings.
Similarly, U.S. Pat. No. 5,656,063 (Hsu) discloses an air cleaner with separate ozone gas and ionized air outputs. Air is drawn through a multi-layered filter, then through an ionizer to induce a negative electric charge. The negative ions precipitate when passing through a filter having a positive charge. An ozone generator mixes with the air to provide further cleansing.
Likewise, U.S. Pat. No. 5,647,890 (Yamamoto) discloses a clog resistant filter to remove fine particulates and an induced voltage electrode to capture contaminant particles in a filter material.
U.S. Pat. No. 5,593,476 (Coppom) also discusses an air filtration apparatus. The device has a fibrous filter positioned between two electrodes, and corona pre-charger positioned upstream of the electrodes and filter.
Finally, U.S. application Ser. No. 2001043887 (Moreault), discusses a device which includes a high mass-flow rate air-mover and a low mass-flow rate ultraviolet decontamination device.
The threat of airborne hazards has created a need for an efficient air purifying system. It is therefore an object of the invention to provide an air purifying apparatus which will effectively kill bacteria, viruses, and the like, as well as filter out contaminants, and harmful or hazardous gasses from a ventilation system, or in an enclosed space.
The foregoing disadvantages of prior devices can be overcome by the present invention by providing a ventilation system, which comprises a housing enclosing a purifying chamber, the housing having an inlet for drawing in contaminated air and an outlet for expelling purified air; a pump for introducing a fluid containing a source of antimicrobial ions into the purifying chamber; at least one microwave radiation source and at least one ultraviolet radiation source, the radiation sources for increasing the effectiveness of antimicrobial ions in destroying airborne microorganisms; a filter for removing airborne particulates; and a filter for adsorbing antimicrobial ions from treated air. Preferably, the antimicrobial ions are derived from a halogen, such as chloride, bromide, or iodide, or a gas or fluid containing chlorine or bromine ions in another form such as hypochlorite ions, for example. The fluid can also be sprayed droplets or vaporized aqueous sodium hypochlorite or similar, antiseptic agent. The apparatus or module can be installed in a new or existing ventilation system, or can be a free standing module.
The module can include a filtration system to remove and collect airborne particles, using physical or electrostatic separation methods, and can also include a filter to adsorb harmful gasses, toxins, or poisons.
The invention also provides a method for cleaning air in a ventilation system, the method comprising: moving a volume of air into a purifying chamber; introducing an ionized antimicrobial fluid in the presence of ultraviolet and microwave energy; and maintaining the volume of air in the purifying chamber for a period of time sufficient to kill airborne microbial matter therein.